Vacuum-insulated truck body



" Nov. 19, 1940..

F. R. BEAL VACUUM-INSULATED TRUCK BODY Filed April 28, 1958 Patented Nov. 19, 1940 UNITED STATES PATENT 5 Claims.

This invention appertains to the art of refrigeration, and more particularly to the design of insulated, truck body construction adapted for the transportation of goods desired to be kept in a ,refrigerated condition.

At the present time truck bodies, designed for the purpose above-described, commonly comprise what may be termed dual wall construction, that is an inner-lining Wall and an outer-lining wall separated therefrom and built around the former between which inner and outer walls insulating material is placed. Such insulating material commonly consists of cork or rock wool.

For the purpose of the construction, such as above-described, and which is commonly used today, the inner and outer walls of the truck body are required to be spaced a considerable distance apart, such as four to eight inches, and the intervening space filled with the insulating material referred "to. Such a construction materially limits the interior space available for the pay load for a given over-all length and width of truck body. In other words, in such constructions there is a tremendous amount of waste space because of the thickness of insulation necessary for a commercially practicable refrigerated truck body. Additionally, of course, the amount of insulating material required in the commonly used truck bodies of this type is a very I considerable itemsince cork and rock wool are very expensive.

It has been proposed heretofore to construct refrigerating containers comprising spaced inner and outer linings, or walls, the space between which is intended to be evacuated, but, so far as i applicant is advised, no practical construction of this type has ever been utilized for the reason that it has heretofore been impossible 'to design such a container, the walls of which were sufiiciently air-tight to maintain a vacuum. It is, therefore; a primary object'of this invention to producea vacuum insulated' truck body construction comprising spaced inner and outer walls, availing of a peculiar method of sealing the ,sheets of metalof whichsuch walls consist, at the a points of joinder of the sheets going to make up the top, bottom, side and end walls of the inner and outer linings. 1

A further object of the invention consists in the provision of a very strong and efficient frame constructionseparating the inner and outer linings of the refrigerated body or container. Such intermediate, or spacing, frame structure is sufficiently strong to prevent the walls from collapsing ss-whentheintervening ispace is evacuated, yet, so

designed that the air may be readily withdrawn from said space.

The merits and advantages of a vacuum insulated, construction over those availing of material, such as-rock Wool or cork, are so obvious as hardly to need pointing out. be mentioned that a construction of refrigerating truck body built in accordance with the invention of applicant has been found to be highly efficient Where the inner and outer walls, or linings, are spaced apart a mere one or two inchescas comparedwith the much wider spacing necessary in constructions availing of material insulation. Truck bodies of the type of applicants are, therefore, much lighter in weight, economical as to pay-load space available and cheaper in construction than refrigerating bodies of the type now used.-

The joining of the sheets of metal comprising the top, bottom, side and end walls of the inner and outer linings, in accordance with the method of the invention, produces such tight seams as to obviate not only any leakage of air therethrough but any leakage of liquid as well. This is advantageous not only because of the desirability of maintaining a vacuum in the space between the inner and outer walls, but from a sanitary standpoint as well. Milk and ice cream, as well as other liquid products, are often transported in these refrigerating truck body containers, and such products are likely to become spilled in handling and tend to leak through the inner walls of truck bodies of the construction now in common use. This results in an unsanitary condition of the refrigerating body for which no remedy is to be had, since the liquid leaking through walls cannot be dried out. It' thus causes rusting and deterioration 'of the metal. In the construction of my invention, however, no such leakage can occur, and, since no moisture can exist in the evacuated space between the Walls, rusting and 40 deterioration from this cause is entirely eliminated.

In the construction of bodies of the type commonly used, the vibration caused by road shock in travel results in materially reducing the eifective life of the body as a refrigerating unit. No method of construction heretofore proposed makes adequate provision for the trussing of the inner and outer walls, and the joined portions of each, so as to prevent relative movement thereof caused by road shock in travel. The insulation between the walls in these bodies becomes frozen in service, causing contraction and breakage thereof, and the vibration of the bodies during However, it may i 5 travel causes downward shifting of the insulation, which thus becomes ineflective to insulate the upper portions of the side and end walls.

All these defects of present day constructions are eliminated in my invention. The bracing structure, separating the inner and outer walls, being extremely rigid acts effectively to truss the inner and outer walls against relative movement. Because of the vacuum therebetween, the inner and outer walls tend to push toward each other through the separating bracing structure. Thus, in the construction of my invention, vibration is greatly minimized or substantially eliminated. This fact is of great importance in extending the life of the body.

An additional important advantage of the method of construction of my invention resides in the ease with which any possible leaks in the seams between the panels of the inner and outer walls may be repaired when necessity arises. Since the joints of the inner container are inwardly extending and exposed, they are readily accessible for repair. Likewise, the joints of the outer container, being outwardly extending and thus similarly exposed, are equally accessible when necessity for repair arises.

Other and further objects and advantages of the invention will readily appear as the description thereof progresses.

In the accompanying drawing:

Figure 1 is a side view, partially broken away and shown in section, of a vacuum-insulated body of the invention.

Figure 2 is a vertical sectional view of the construction shown in Figure 1 looking toward one end thereof.

Figure 3 is an interior perspective view looking toward one corner of the inner container.

Figure 4 is a perspective view, in vertical section, looking toward one end of the body.

Figure 5 is a perspective view showing the construction of the spacing brace structure.

Figure 6 is a horizontal sectional view taken on the line 66 of Figure 1.

Figure 7 is a perspective view illustrating the floor panel of the inner container showing the manner in which the side and end flanges are bent inwardly and sealed at their intersecting corners.

Now describing the invention in detail, the inner container comprises a floor panel I comprising a sheet of metal inwardly bent at its edges to form the side flanges 2 and 3 and the end flanges 4, one of which only is shown in the drawings. The flanges 2, 3 and 4 of the bottom panel are bent inwardly at an angle of 45 with respect to the main portion I thereof. The adjoining corner portions of the flanges 2, 3 and 4 are sealed along their lines of juncture as at 5 and 6.

The side wall panels 1 are formed at the bottom with flanges 8, bent inwardly at an angle of 45, end flanges 9 bent at the same angle and top flanges l0 inwardly bent at an angle of 90. The adjacent corner portions of the flanges 8, 9 and H] are joined together along their respective lines of juncture by welding in a manner similarly described in reference to the flanges of the floor panel. The end panels H are formed similarly to the side panels I and comprise bottom and side flanges l2 and I 3, inwardly bent at an angle of 45, and the top flanges l4 inwardly bent at an angle of 90. The flanges I2, l3 and M are joined together at adiacent corner portions thereof by welding in a manner similar to that described in reference to floor panel I.

One of the side panels I is then assembled in relation to the floor panel I by placing the flange 8 in abutting position with respect to the flanges 2 or 3, as shown in Figure 3. Said side panel is then joined to the floor panel by welding together the edges 8 and 2 of the flanges 8 and 2 respectively. Next an end panel H is assembled in relation to the floor panel I with the bottom flange I2 of the former in abutment with the end flange 4 of the latter. The side flange !3 of the panel II will now be in abutment with the end flange 9 of the side panel 1. The flanges 9 and [3 are now joined together by Welding as are the flanges 4 and I2.

The other side and end panels I and H are assembled relatively to the bottom panel I, and to each other, in a similar manner and their abutting flanges joined together as above described.

The roof panel I5 is curved transversely, as shown in Figure 2, and has longitudinal flanges i6 bent inwardly at an angle of approximately 90 to fit in abutting relation with the top flanges I0 of the side panels I. The roof panel also has transverse flanges I! at each end thereof which are similarly bent inwardly at an angle of approximately 45. End panels l8 are of a shape to fit between the top flanges M of end panels H and the transverse flanges I! of roof panel l5, said panels l8 being provided with flanges, not shown, adapted to fit in abutting relation with the flanges l1 and also provided with flanges l9 adapted to fit in abutting relation with flanges M of end panels II.

The roof panel 15 is joined to the side panels I by welding together the flanges l6 and I0 respectively thereof. The end panels l8 are joined to the roof panel 15 and end panels II by welding together their abutting flanges.

From the above description, it will be seen that there is provided an inner container, the joints of the various panels of which are tightly sealed to provide an air-tight container, the inwardly protruding adjoining flanges being readily accessible from the inside of the container for the purpose of repair or re-sealing thereof should occasion ever arise.

The spacing structure separating and bracing the inner and outer containers comprises strips of wood, preferably, of a width equal to the distance between the walls of the container. Certain of the wood strips 20 are positioned longitudinally of the body and others, indicated by the numeral 2|, are positioned vertically, as shown in Figure 1, respecting the sides and ends of the body, or transversely thereof respecting the roof and floor of the body.

Each of the strips 20 and 2| is grooved along one edge as indicated at 211 and Zi respectively. Each of the strips is notched at intervals throughout its length as at 20 and 2N, said notches extending half the width of said strips. The cooperating notches 20 and 2| enable the strips 20 and 2| to fit together to form a rigid framework. Sheets or panels 22 of fiber board or plywood are nailed or otherwise secured to the flat edges (those opposite the grooved edges) of the strips comprising the separating framework.

When thus constructed the framework separating the inner and outer side walls is positioned so that the fiber board or plywood sheet 22 is against the outer side walls 23 and the grooved edges 23 *23 are against the inner side walls l.

The same is true respecting the'framework separating the inner and outerroofand end walls. In reference to the framework separating the floor panels l and 24, however, the fiber board or plywood 22 is positioned against the inner,

floor l, and the grooved edges 2fl -2l fagainst the outer floor 24. This provides greater rigidof .the various side, end, roof and'bottom panels f are bent outwardly instead of inwardly as is true in reference to the inner container. The upper, flanges 25 of the outer side panels 23 are bent outwardly at an angle of 90 and then upwardly, preferably, as indicated at 25. The flanges 26 of the roof panel 3| are similarly bent and the flanges 25 and 26 are then joined together by welding their meeting edges as at 21. A dripmold is thus formed by the flanges 25 and 26.

At its ends and sides the outer bottom panel 24 is flanged downwardly, as shown at 28 and 29 in Figures 4 and 2 respectively. The flanges 28 and 29 are joined by welding at their corner edges and then the bottom panel is joined to the end and side panels by welding the bottom edges of said panels to the bottom edges of said flanges as indicated at 30.

The outside container may preferably be rounded at the corners for the sake of attractive appearance as shown by Figure 6. For this purpose a rounded sheet 32 flanged outwardly at 33 and 34 is joined to the side and end panels 23 and 35 respectively by welding together the flanges 33 and 36, as at 31, and the flanges 34and 38 as at 39. v

The body, constructed as above described, may be mounted upon a truck chassis or frame in any suitable manner, but I preferably avail of two longitudinal channel members 40 and 4| at each side of the body which clamp between them the bottom edge 42 of the side panels 23 and flanges 29 of the bottom panel 24. Bolts 43, provided with suitable nuts, pass through the channel members for clamping the same together.

At intervals throughout the lengths of the channel members 4| lugs 44 are welded thereto and suitably secured to channel members 45 of the truck chassis. Sill beams 46, resting on the lugs 44, support the sub-floor 41 which adds to the rigidity of the construction.

Since ordinarily the walls of a body constructed in accordance with the invention will each require a plurality of sheets of metal joined together, such sheets may be flanged inwardly, respecting those constituting the inner container, where they are to be joined, at a 90 angle as are the flanges 49 and 50, and welded together at their abutting edges. The sheets constituting the panels of the outer container will be flanged outwardly at their points of joinder as are the flanges 5! and 52, and similarly welded.

For access to the interior of the body a door will be provided of a construction similar to that of the rest of the body. That is, it will comprise inner and outer walls spaced from each other in the same manner as the walls of the inner and outer containers. The door will be provided, intermediate its inner and outer walls, with the spacing structure comprising the members 20 and it! and attached plyboard sheet 22. The door frame will be suitably sealed with reference to the space between the inner and outer containers,

and preferably recessed and provided with a rubber sealing flange, the door being provided with suitable cooperating rubber sealing flanges becoming seated in the recess of the door frame when the door is closed.

A flexible tube is provided connecting the interior space between the inner and outer walls of the body with the interior space between the in ner and outer walls of the door. Said interior space between the inner and outer walls of the body will be connected by pipe or hose to a vacuum pump conveniently located upon the truck chassis and operated by the truck engine. Since the separating frame between the inner and outer containers is inherently porous, being of wood,.

and the grooved edges of the members 20 and'2l make it additionally air conductive, the intervening space between said containers may readily be evacuated by the vacuum pump.

It will be noted that, while all joints in the construction above described are absolutely airtight, they are flexible as well because of the method of sealing by welding at the edges or abutting flanges. This fact is important since it enables the air pressure within the inner con tainer and outwardly of the outer container to press the respective walls thereof more tightly against the separating frame, thus providing increased rigidity of the construction and minimizing anytendency of the walls thereof to vibrate or shift relatively to each other.

Since the structure herein described is merely given as an example of the manner of construction of a vacuum insulated body in accordance with my invention, I do not intend to be limited in any way to the details thereof except as defined by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A vacuum insulated truck body construction comprising spaced inner and outer containers, and a spacing structure between said containers separating the same from each other, at least one of said containers being formed with top, bottom, side and end walls of flexible metal, each wall having a marginal portion bent away from the normal plane of said wall and the extreme edge only of said marginal portion being joined to the extreme edge only of the adjacent marginal portion of another of said walls to provide a substantially air-tight, yieldable connection therebetween, thereby enabling the walls of said container to be relatively movable in their respective planes.

2. A vacuum insulated truck body construction comprising spaced inner and outer containers, and a spacing structure between said containers separating the same from each other, each of said containers being formed. with top, bottom, side and end walls of flexible metal, the edges of the walls of the outer container being bent outwardly away from thhe normal planes of said walls, the edges of the walls of the inner container being bent inwardly away from the normal planes of said walls, and the extremity only of each edge of each wall being joined to the extremity, only of the adjacent edge of another wall of the respective container whereby the conjunctive seams of the respective containers will be exposed and readily accessible, the seams of the outer container outwardly thereof and the seams of the inner container inwardly thereof, the joinder of the walls of said containers providing substantially air-tight yieldable connection between adjacent walls of the respective containers thereby enabling said containers to be tightly and yieldably pressed against said spacing structure by atmospheric air pressure when the space intermediate said containers is evacuated.

3. A double walled structure for truck bodies comprising spaced inner and outer containers, each composed of abutting plates or panels, said panels having marginal flanges disposed at the outer and inner sides respectively of the outer and inner containers, and the adjacent panels of the respective containers being connected together only at the extreme outer edges of adjacent flanges of said panels, the connections between said panels constituting readily accessible flexible connections permitting relative movement of the panels in their respective planes upon distortion of the structure.

4. A double walled structure for truck bodies,

such wall being composed of a plurality of abutting plates or panels, said panels having marginal connecting flanges, the abutting flanges of respective adjacent panels having their outer extremities only fused together, whereby to provide flexible connections between said panels permitting movement of the panels with respect to each other upon distortion of the structure.

5. A double walled structure for truck bodies,

each wall being composed of a plurality of abutting plates or panels, said panels having marginal connecting flanges, and said panels being joined by welding together the outer extremities only of abutting flanges, whereby to provide flexible connections between said panels permitting 15 relative movement of the panels in their respective planes upon distortion of the structure.

FRANCIS R. BEAL.

CERTIFICATE OF CORRECTION. Patent No. 2 ,222,065 0 November 19, 191mm FRANCIS R BEAL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows Page it, second column, line 1, claim h, for the Word such" read --each-*-; and that the said Letters Patent shonld be read with this correction therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 51st day of December, A. D.. l9LlO Henry Van Arsdale;

(Seal) Acting Commissioner of Patents 

